In the production of pulp for the making of paper and the like, and in the production of other articles from wood chips, it has been found to be economically feasible to take whole trees and turn them into chips in the field. Several problems that have been associated with commercial prior art devices, of which the device disclosed in U.S. Pat. No. 3,661,333 is an example, for turning whole trees into chips in the field have been the large size of the apparatus used and the vehicles associated therewith, and the large amount of down-time required due primarily to jamming of the feed mechanisms therefor. According to the teachings of the prior art, a whole tree is lifted or heeled onto a conveyor chain by a knuckle boom with a heel plate, which conveyor feeds the tree to various feed rolls, and then on into a chipper. In operation, large tree limbs often result in jamming of the feed mechanism, and jamming also results from debris being caught in the conveyor mechanism. Jamming of the feed mechanism usually requires the operator to hand-cut the jamming material from the feed mechanism, resulting in a great waste of time, and consequent reduction in any economic advantages of whole tree chipping in the field.
According to the teachings of the present invention, a feed mechanism is employed that substantially reduces the down-time of a whole tree chipper, and in addition provides for a whole assembly that is lighter in weight and smaller in size, and that does not require nearly as large a boom mechanism for bringing cut trees into operative engagement with the assembly, or if the same size boom is employed no heel plate is needed and tree manipulative ability is increased. According to the present invention, the conveyor chain is eliminated and a particular funnel is used to reduce hang-ups. The funnel provides for deflecting of the tree limbs so that they may be engaged by feed rolls and fed to the chipper. Preferably, the funnel is rotatable and has particularly disposed teeth along the interior surface thereof so that should a large limb or the like jam the feed orifice, rotation of the funnel will automatically be initiated, and the obstruction will be cut off and/or twisted so that feed to the feed rolls will not be prevented.
The feed rolls according to the present invention are movable toward and away from each other and biased toward each other by a gripper ram, and the rolls assembly itself is movable with respect to the funnnel orifice by a floating ram, which also provides a particular bias. Thus, the feed rolls are free-floating, and will assume any required orientation in their plane of movement with respect to the funnel orifice to accommodate variously sized and positioned trees.
Since there is no conveyor for bringing cut trees to the chipper according to the teachings of the present invention, there is no need to provide a large knuckle boom to lift the trees -- instead, a smaller boom-mounted grapple or the like may be provided to merely drag a cut tree to the apparatus of the present invention, and lift only the trunk portion thereof off the ground into the funnel orifice, while the rest of the tree rests on the ground. Also, it is preferable to further ensure that no hang-ups will occur at the chipper itself by making the funnel orifice slightly smaller than the chipper orifice.
Since there is no cumbersome conveyor mechanism, and since the boom may be much reduced in size, all the advantages attending a smaller mechanism ensue, such as more maneuverability to position the apparatus in the most advantageous position, no special road permit being required to move the apparatus on the road, reduced construction costs, reduced fuel consumption for running and moving the apparatus, and fewer parts used in the construction and thus less required maintenance.
The principal object of the present invention is to provide an improved method and apparatus for total tree chipping. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.